1. Field of the Invention
The present invention relates to a method for controlling noise reduction of an air conditioner, and more particularly to a method for controlling noise reduction of an air conditioner, in which an outdoor fan is continuously operated under the condition that a compressor is stopped, thus reducing noise generated due to flow of a refrigerant when the compressor is stopped.
2. Description of the Related Art
Generally, an air conditioner, serving as a cooler, a heater and/or an air cleaner, is an appliance for cooling, heating and/or cleaning indoor air, thus providing a comfortable indoor environment.
FIG. 1 is a schematic view of a conventional air conditioner operated in a cooling cycle, and FIG. 2 illustrates graphs respectively showing operating states of a compressor and an outdoor fan when the conventional air conditioner is stopped.
As shown in FIG. 1, the conventional air conditioner, operated in the cooling cycle, comprises a compressor 2 for compressing a refrigerant into a high-tempereature and high-pressure gaseous state, a condenser 4 for condensing the refrigerant passing through the compressor 2 into a medium-temperature and high-pressure liquid state, an expansion device 6 for decompressing the refrigerant passing through the condenser 4 into a low-temperature and low-pressure liquid state, and an evaporator 8 for evaporating the refrigerant passing through the expansion device 6 into a low-temperature and low-pressure gaseous state. Here, the compressor 2, the condenser 4, the expansion device 6 and the evaporator 8 are connected by a refrigerant pipe.
In the air conditioner operated in the cooling cycle, an outdoor fan 12 for blowing outdoor air is installed adjacent to the condenser 4, and an indoor fan 14 for blowing indoor air is installed adjacent to the evaporator 8. Such an air conditioner is controlled by a control unit.
Hereinafter, operation of the above-described conventional air conditioner will be described in detail.
First, when the air conditioner is started, the compressor 2 is operated, and then the refrigerant circulates along the compressor 2, the condenser 4, the expansion device 6 and the evaporator 8, sequentially. Here, the outdoor fan 12 and the indoor fan 14 are operated. Accordingly, the refrigerant passing through the condenser 4 is heat-exchanged with the outdoor air blown by the outdoor fan 12, and is then condensed. Further, the refrigerant passing through the evaporator 8 is heat-exchanged with the indoor air blown by the indoor fan 14, thus cooling the indoor air.
When the air conditioner is stopped, as shown in FIG. 2, power, which is provided to the compressor 2 and the outdoor fan 12, is switched off, thus simultaneously stopping the compressor 2, the outdoor fan 12 and the indoor fan 14.
When the air conditioner is stopped as described above, the refrigerant flows from the compressor 2 and the condenser 4, having comparatively high inner temperature and pressure, to the expansion device 6 and the evaporator 8, having comparatively low inner temperature and pressure, until the inner pressures of the compressor 2, the condenser 4, the expansion device 6 and the evaporator 8 reach an equilibrium state.
When the air conditioner is stopped, the compressor 2 and the outdoor fan 12, etc. are all stopped. Accordingly, the refrigerant flows from the compressor 2 and the condenser 4, having comparatively high inner temperature and pressure, to the expansion device 6 and the evaporator 8, having comparatively low inner temperature and pressure, thus generating noise. Particularly, the noise generated due to the flow of the refrigerant, has a designated frequency band, and is transmitted into an indoor space along the refrigerant pipe, thus causing indoor users to experience an unpleasant noise.